Balanced slide-valve



(No Model.)

E'. LLoYD.-

BALANGBD SLIDE VALVE.

Patented Jan. 23, 1894;

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UNITED STATi-:s`

ATENT OFFICE,

EDWVIN LLOYD, OF HARVEY, ILLINOIS.

BALANCED SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 513,119, dated January23,'1894.

Application filed January 3, 1893. Serial No. 457,1'77. (No model.)

.To all whom it may concern:

Be it known that I, EDWIN LLoYD, a subject of the Queen of GreatBritain, about to become a citizen of the United States, and a residentof Harvey, county of Cook, and State of Illinois, have invented certainnew and useful Improvements in Balanced Slide-Valves, of which thefollowing is a specification.

My invention relates to slide valves which are balanced by means ofresistance in an opposite direction, thus relieving the valve by takingthe pressure caused by the steam away from the back of the valve, and ithas for its object the provision of adevice simple in construction,inexpensive in manufacture or application to an engine, and efficient inpractical use.

To attain the desired end my inven tion consists in the construction andarrangement of parts first fully set forth and then pointed out in theclaims. y

In the drawing which is a view in vertical section of a balanced slidevalve constructed according to my invention, A, represents a slide valveinclosed in a stealn chest which is preferably provided With ahorizontal steam cylinder A' in which Works a plunger or balancingpiston a, preferably working at right angles to the slide valve A, thebalancing piston rod b, and the slide valve link B, being respectivelypivoted to the ends of and connected by a vibrating bell crank O,`iournaled at O' to one or both sides of the horizontal steam cylinderA' The relative areas of the slide valve A, and of the balancing pistona, should be equal, or in lieu thereof leverage should be allowed in thebell crank C. For instance if the horizontal end of the hell-crankshould be one and one half inches long, and the perpendicular end threeinches the area of the balancing piston may be proportionately smallersay approximately one half that of the slide valve. The perpendicularend of the bellcrank may be provided with a slotin order that inOperation the balancing piston rod may at all times occupy a horizontalposition. The slide valve link or lifter B, is preferably pivoted to theback of lthe slide valve midway of its length, although it may be rigidand the horizontal arm of the bell crank slotted, and serves to lift orrelieve the slide valve A, from undue pressure against its gineer of alocomotive has a light load or is running down grade he hooks up thelink and shortens the travel of the slide valve, whereas for heavy loadsor going up grade the engineer throws the link down and lengthens thetravel of the slide valve; thus the ordinary unbalanced slide valve intime wears its face or seat .h0llow, and consequently the steam flowsthrough this Opening and much fuel is wasted, which evil is obviated bythe use of my invention.

With a balanced slide valve Constructed according to my invention thelost motion caused bywearof the partsistaken up. Oonsequently thedeviceis self-adjusting as when the parts become worn the balancingpiston simply travels out a little farther. A slide valve thus balancedwill work easily and smoothly on its seat Without undue pressure uponthe back of the same, and an engineer can reverse his engine easilywithfull pressureof steam on.

It is obvious that the relative positions of the slide valve andbalancing piston may be varied according to the particular circumstancesof their use. My balanced valve can be applied to any engine already inuse at a comparatively small expense, and being simple in constructionis not liable to get out of repair.

There is much less possibility of the eccen` tric slipping by my deviceas all it has to do is to move the weight of the valve, valve rod andeccentric rod to and fro.

My balanced valve reduces the frictlon and works easily both under highand low pressure of steam. It will be observed that the bell crank pullsagainst both the slide valve and balancing piston in lines approximatelyat right angles to their longitudinal axes, thus attaining the highestefficiency at a minimum expense,`

Another advantage of my valve is that it is a great economizer of steam,as by reducing the burden of the engine-the amount of pressure on thevalve each stroke-a smaller quantity of steam may be used than hashitherto been required and there is thus a great saving of fuel.

It will be observed that by my improved construction there is no weightof the piston a to be supported vJoy the slide valve A, and

` only part of the weight of the rod connected therewith to be similarlysustained. In the old forms of balanced slide valves the press-` ure ofthe steam has to overcome the weight of the balancing pistou, &c., whichis a constant dead weight, and consequently the pressure against theslide Valve and balanoing piston will not be equal, or in the sameratio, as, the lower the pressure of steam, the greater in proportionwill be the said dead weight to overcome. By the use of my horizontalsteam cylinder this objectiou is overcome and my improved balanced valveis rendered more compact and therefore suitable for use on locomotives.

As it is evident that many slight changes in the construction andrelative arrangement of parts might be resorted to Without departingfrom the spirit and scope of my invention, I

would have it understood that I do not restrict myself to the particularconstruction and arrangement of parts shown and described but that Ireserve the right to make such changes and that What .I claim as new,and desire to secure by Letters Patent, is-- 1. The combination with asteam engine slide valve and its inclosing steam chest, of a horizontalsteam cylinder and of a balancing piston, and piston rod connectedtherewith, and of a link pivoted midway to the back of the slide valve,the said rod and link being respectively connected by a bell crankjournaled within the said steam ohest.

2. The combination With the slide valve A, and link B, and inclosingsteam chest, and with the balancing piston a, and rod b, located withina horizontal steam cylinder, of the interinediate bell crank O.

In testimony of the foregoing specification I do hereby sign the same,in the city of Harvey, county of Cook, and State of Illinois, this `thday of November, A. D. 1892.

EDWIN LLOYD.

Witnesses:

FRANK M. GRoU'r, JASPER J. MULLIN.

